Malicious PDF — malware analysis report

Static analysis result for SHA-256 4918e908c537647a…

MALICIOUS

PDF

81.8 KB Created: 2021-06-09 22:17:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: aeadb523202da96017caac62cb1cb936 SHA-1: d9e87827bcdece0768c10496ad97fbc2e441d8b7 SHA-256: 4918e908c537647af0388b5e21a9fb9242789699e9ac7ae53bf37b162e9d3a0b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF document is disguised as a worksheet answer key to trick users into downloading it. It contains numerous links to external websites, many of which are hosted on compromised CMS platforms, suggesting a phishing or malware distribution campaign. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://huntic.ru/uplcv?utm_term=romeo+and+juliet+elizabethan+language+worksheet+answers PDF link annotation
    • https://njsolarpower.com/wp-content/plugins/super-forms/uploads/php/files/6d12bc1d23972c63e995eed13d03be84/dugimesenumofasewomilujos.pdfIn PDF document text
    • https://www.cfo-search.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089843d74024---nixezogokavezejofotofuxa.pdfIn PDF document text
    • http://fouladsazanco.com/Upload/file/lorezenugebis.pdfIn PDF document text
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160a24a57837cf---17591190431.pdfIn PDF document text
    • https://www.simcoerecovery.net/wp-content/plugins/super-forms/uploads/php/files/eklvaeiuftautp3d0e3v97479o/23110972850.pdfIn PDF document text
    • https://actioncoach.com.my/wp-content/plugins/formcraft/file-upload/server/content/files/1607c136e538ba---72575645351.pdfIn PDF document text
    • http://bajcsidavidfoto.com/_user/file/botonevago.pdfIn PDF document text
    • http://www.zopfitravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b1070017025---zinakuni.pdfIn PDF document text
    • https://swimproject.eu/wp-content/plugins/super-forms/uploads/php/files/204635bd396ddd08662b71c8671e67a7/miregowapepiwokenilusufik.pdfIn PDF document text
    • https://broadstripe.com/wp-content/plugins/super-forms/uploads/php/files/8407f9bc61e4798461eadf43f5d1376d/13489512535.pdfIn PDF document text
    • https://fjordancv.info/wp-content/plugins/super-forms/uploads/php/files/c05e05a1c238bf0b76b913a1205f4da1/paviveluk.pdfIn PDF document text
    • http://www.hj-bouwt.be/wp-content/plugins/formcraft/file-upload/server/content/files/160a5e4455dae9---55015255735.pdfIn PDF document text
    • https://www.citysecurity.org.uk/wp-content/plugins/super-forms/uploads/php/files/ikktt53bapkbvh98urfer5n93r/15134901399.pdfIn PDF document text
    • https://eseninternational.com/uploads/files/39791370193.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010388.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10388 5668 bytes
SHA-256: 8143504873224054c4be125652c9b9421fdd6079799a2619bb8eaadb80db194e
font_01_sfnt_off000116bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116BF 10748 bytes
SHA-256: ef8befe83fbe6e58c36af51b6e203378a3398bb10438fb78a456f3571d1f80a7